In imaging apparatuses, such an art has been known that a driving method of a sensor is varied so as to output images with different resolutions. Such art is disclosed in Japanese Patent Laid-Open No. 2003-134386, for example.
Also, an imaging apparatus having a resolution conversion circuit is disclosed in Japanese Patent Laid-Open No. 2004-112579, for example.
FIG. 15 shows a block diagram of a conventional imaging apparatus. As shown in the figure, the imaging apparatus comprises an imaging circuit 1501, a memory circuit 1502, a YC processing circuit 1503, a resolution conversion circuit 1504, a compression conversion circuit 1505, a recording circuit 1506, and a display circuit 1507. The YC processing circuit 1503 reads out RAW data stored in the memory circuit 1502, converts it to YC data, and output it to the resolution conversion circuit 1504.
The resolution conversion circuit 1504 applies resolution conversion processing to an input image generated at the YC processing circuit 1503 and generates two image data: an image for display and an image for record. The resolution conversion circuit 1504 writes the two image data in two regions in the memory circuit 1502, respectively. A user sets the numbers of pixels and lines of the input image, the image for display and the image for record in advance in the resolution conversion circuit 1504.
The resolution conversion circuit 1504 is configured so as to process the input image for each line. The resolution conversion circuit 1504 executes image generating processing by determining which of the image for display and the image for record is to be generated every time the input image is processed for one line. For example, suppose that after a line L of the image for display is generated, the resolution conversion circuit 1504 determines which of the image for display and the image for record is to be generated and as a result, a line M for the image for record is generated. After that, the resolution conversion circuit 1504 further determines which of a line of the image for display (L+1) and a line of the image for record (M+1) is to be generated.
In the conventional imaging apparatus described for the first, images with a plurality of resolutions are obtained by changing sensor driving. However, the plurality of images with different resolutions can not be outputted at the same time. In the other conventional imaging apparatus, the resolution conversion circuit stores a plurality of images with different resolutions in the memory circuit and a compression conversion circuit reads out the plurality of images from the memory and executes compression. In this case, the imaging apparatus needs to be configured so that the compression conversion circuit makes an access to the memory circuit to which the resolution conversion circuit outputs the image data. That means that a plurality of circuits access the single memory circuit, which needs arbitration of memory accesses, and it is desirable that such configuration is avoided.